Furnace.



A. SIVIALLWOOD.

FURNACE.

APPLICATION FILED IuIIE I9. 1915.

3l,2%,%? Patented May 15, 1917.

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A. SMALLWOOD.

FURNACE.

APPLICATION FILED IUIIE I9, 19I5 Patented May 15, 1917.

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FURNACE.

APPLICATION FILED IuNE I9. |915.

Patented May 15, im?.

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UNTTFD ESTATES FATTNT @Fl-FTW@ ALFRED SMALLWOOD, OF LON DON ENGLAND, ASSIGNOR TO AMERICAN INCANDESCEN T HEAT COMPANY, OF PORTLAND, MAINE, A CORPORATION OF IlUINE.

FURNACE.

Application filed June 19, 1915.

To all whom it may concern.

Be it known that I, ALFRED SMALLwooD, a subject of the King of Great Britain, residing in the city of London, England, have invented certain new and useful Improvements Relating to Furnaces, of which the following is a full description and specification.

This invention relates to furnaces embodying the broad invention disclosed in my co-pending application, Serial No. 862,753, filed September 21, 1914, and shows a particular application of that invention to furnaces having a plurality of working chambers. By the use of my present invention such furnaces can be constructed, which can be operated economically from a single fire grate, and in which the temperatures of the separate working chambers can be independently controlled without changing the firing of the furnace.

In the accompanying drawings I show, by way of example, a furnace adapted for annealing or other metal treatment, in which my invention is embodied, and in which:

Figure 1 is a sectional view, on the line I I of Fig. 2; 2 is a sectional view on line II-II of Fig. 1; Fig. 3 is a sectional view on line IIIHIII of F ig. 1; Fig. 4i is a sectional view on line IV-IV of Fig. 1, and Fig. 5 is a sectional view on line VHV of Fig. l.

In the specimen furnace shown in these drawings, 2 is a fire grate, which may be of ordinary construction, and the numeral 3 represents the main reservoir in which combustion is carried toward completion and which is preferably made with thick walls of irebrick. The reservoir 3 may be separated from the lire grate 2 by a bridge wall 4, through which may pass an air passage 5. The air passage 5 should be used if it is desired to have an oxidizing atmosphere in the working chamber of the furnace; however, if a non-oxidizing atmosphere is desired in the working chamber the passage 5 should not be used, and all of the oxygen for combustion should be admitted through the grate bars. If desired, the air admitted to the grate 2 and the passage 5 may be previously heated in any well known manner to give economy of combustion. From the reservoir 3 run passages 6, 7 and 8, through which heat can flow to radiating Specification of Letters Patent.

`the heat to flow .Patented May 15, 191'?. Serial No. 35,061.

chambers A', B and C mediately above B and C.

respectively. Imthe radiating chambers Ii, and separated rom them by relatively thin irebrick partitions 9, are the Y' working chambers A., B and C. As shown in Figs. 1 and 2, the radiating chambers A', B and C are each provided with walls 10 and 11, which provide an extended surface for holding heat and which cause in one direction at the center of the partition 9, and in the opposite direction at the sides. et thesides and ends of the chambers A', B and C are fines 12,

The ilues 12 connect the chambers A', B and C with working chambers A, B and C and are provided with dampers 13. The

`connected with said chambers by ports 12.

dampers 13 that lie in the exterior walls of l the furnace can be operated directly. In order to operate those that lie within the partition walls T supply passages 13 extending to the front of the furnace, and of a height greater than the thickness of the dampers. To operate these dampers a metal rod with a hooked end is inserted in the passage 13', and the dampers are pushed or pulled forward or backward. The iiues 12 are preferably inset into the walls of the furnace, shown in Fig. 1, instead of passing through the partition 9, for such a construction both adds to the already extended surface which is adapted to hold reserve heat, and also renders it possible to direct the heat to better advantage, while providing a more lasting type of construction. By splitting the path of the heat in the manner shown, and by positioning the lirst lues through which the heat passes to the working chambers at the opposite end of the chamber from that at which the heat first meets the partition 9, a balance of heat is maintained, which insures an even heating of all parts of the working chamber.

Inasmuch as the lues through which the heat first enters the working chambers A, B and C are at the front of said chambers, I withdraw the gases at the rear, further to insure an even distribution of heat, and for this purpose I supply the counter-arches 14 under which the gases pass. I then cause the gases to flow through the dues 15 over the tops of the working chambers and thereby furnish radiation of heat from the roofs of the working chambers. Ultimately the gases pass through the flue 16 and out through the stack 17. A damper 18 may be positioned in the flue 16 near the stack 17.

The exact proportioning of the parts of the furnace Will depend on the conditions under which it is used, but by Way of eX- ample, if such a furnace as that illustrated is to be used for annealing, I have found that good results can be obtained if the grate 2 is made with an area about one-eighth that of the combined floors of the Working chambers; the main heat chamber 3 With a crosssectional area about two-thirds of the area of the grate 2, and a length sufficient to traverse the Working chambers A, B and C;

the total area of the passages 6, 7 and 8 about two-thirds the cross-sectional area of the main heat chamber 3; the total area of the ports 12 in each of the chambers A, B and C equal to the area of the passages 6,7 or

8 leading into such chamber, and the seo.

tional area of each of the flues 16Vabout two-thirds of .the area of the corresponding passage 6, 7 or 8. I do not, however, Wish to limit myself to these proportions, as they can be materially altered Without rendering my furnaces inoperative.

If the furnace embodying my invention is to be used for other purposes than anneal-V ing, it may be necessary to change the shape of the Working chamber, which of course can be done Without changing my invention. Hence, in stating What I claim to be my invention, I use the term Working chamber as broadly covering the place Where the heat is to be utilized. It is also apparent that many other changes can be made Without departing from the spirit of my invention, Y

common combustion chamber, a heat-distributing chamber for each of said Working chambers, said heat distributing chambers having extended surfaces for the absorption of heat and being adapted to radiate ieat to the working chambers, flues connecting such heat distributing chambers With the Working chambers, and control dampers for said flues.

2. In a furnace, a plurality of Working chambers, a place forinitial combustion, a common combustion chamber, an intermediatecombustion chamber for each Working chamber, such intermediate combustion chambers having an extended surface for the absorption of heat and being adapted to give an even distribution of heat to each Working chamber, both directly and by radiation. Y

3. In a furnace, a plurality of Working chambers, a place for initial combustion, a

' heat reservoir comprising a main heat chamber in Which combustion may becontinued and from which only a relatively small amount of heat can pass by radiation and a plurality of radiating chambers,each one of which is adapted to radiate heat into one of said Working chambers, flues connecting said radiating chambers Withsaid Working chambers, and dampers adapted to control thepassage of gases through said fines.,

ALFRED SMALLWOOI).

Copies o1' this patent may be obtained for ive cents each, by addressing Vthe'"Commissioner of Patents,V

Washington, D. C. f 

